Accordion is a solitaire game using one deck of playing cards. The object is to compress the entire deck into one pile like an accordion.

The cards are laid out one by one and are immediately put into play if possible. The number of cards to be laid out range from just one card to how many cards the width of the table can allow (usually a second or third row is constructed in the process). While practical, it also allows an element of surprise as the player does not know the next card to be dealt until all possible plays are exhausted.

A pile can be moved on top of another pile immediately to its left or separated to its left by two piles if the top cards of each pile have the same suit or rank. Gaps left behind are filled by moving piles to the left. [Wikipedia]